There has been resurgence of interest among otolaryngologists in the morphological features of the lateral wall of the nasal cavity with the advent of endonasal endoscopic sinus surgery. Functional endoscopic techniques, being minimally traumatic, have become increasingly popular in diagnostic and therapeutic aspects of nasal and sinus problems.
The area termed the “ostiomeatal complex” of the middle meatus has not only the primary maxillary ostia (“PMO”) opening in the hiatus semilunaris (“HS”) but also often includes, other “holes” or accessory maxillary ostium (AMO). It has been estimated that anywhere between 5-30% of the normal population has an AMO located in the maxillary fontanelle (anterior or posterior).
AMO is invariably solitary but occasionally multiple, either congenital or secondary to disease process. A possible mechanism of formation of accessory ostia is obstruction of the main ostium by maxillary sinusitis or due to anatomic and pathologic factors in the middle meatus resulting in the rupture of membranous areas known as fontanelle (certain regions in the middle meatus located below the uncinate process and above the inferior turbinate, covered by nasal mucous membrane medially and mucosa of maxillary sinus laterally with connective tissue sandwiched between the two).
In the past, a naso-antral window procedure was performed for purposes of ventilation and drainage of the maxillary sinus cavity. However, the naso-antral window procedure has the disadvantage of requiring one or more punctures through thick bony tissues in the inferior meatus.